This invention relates to a headphone for use with a small-sized cassette tape player, and more particularly to a headphone having a collapsible structure.
Recently, headphones for use with portable, small-sized cassette tape players are required to be smaller in size and lighter in weight than those intended for indoor use. In addition, the entire structure is required to be collapsible for each storing during non-use.
FIGS. 1(a) and 1(b) show a prior art headband having a collapsible structure. A pair of headband arms 1L and 1R, made of stainless steel, synethetic resin or the like are designed so that the headphone as a whole can be small in size and light in weight. One end of each heandband is pivotably coupled to a single joint member 2 as shown in FIG. 1(b). The joint member 2 has a U-shaped cross section. The headband arms 1L and 1R are each uni-directionally foldable through 90.degree. around the pivot pins 6 from the fully open position of 180.degree..
Furthermore, the other free ends of the headband arms 1L and 1R are pivotably coupled to other joint members 3 which have the same structure as that of the joint member 2. Likewise, a pair of the phone units 4L and 4R are pivotably coupled to the other ends of these joint members 3. In addition, the headband arms 1L and 1R and the phone units 4L and 4R are foldable in a closed direction for easy storing when not in use (FIG. 2). In FIG. 2, reference characters 5L and 5R denote ear-contacting pads made of urethane or the like.
As has been apparent from the foregoing description, the following steps are required to collapse the prior art headphone for the storage: folding of the headband units 1L and 1R at the joint member 2, and further folding of the headband arms 1L and 1R around the joint members 3. In other words, three joint actions have been needed for the prior art foldable headphone. In some cases, the prior art headband foldable in the closed direction would cause unfavorable results of tangling or twisting upon the folding or opening operation due to the fact that the rotational paths of the arm members are included substantially in a single plane.